Peripheral and Central Pathological Mechanisms of Chronic Low Back Pain: A Narrative Review

Investigating the potential of minocycline in reducing brain inflammation in chronic low back pain: a randomized, placebo-controlled mechanistic clinical trial

ABSTRACT

Our group has shown that translocator protein (TSPO) levels, a putative marker of neuroinflammation, are increased in the brain and spinal cord of patients with chronic low back pain (cLBP). Whether neuroinflammation might be a therapeutic target for this condition is unknown. In this phase II double-blind, placebo-controlled, randomized clinical trial, we sought to evaluate whether the tetracycline antibiotic minocycline, which is commonly used as a glial inhibitor in preclinical models, has an effect on brain TSPO levels in adults with cLBP. Participants randomly received 100-mg minocycline or placebo, once a day for 2 weeks. The primary outcome was the change (pretreatment vs posttreatment) in thalamic TSPO levels, measured using [11C]PBR28 positron emission tomography signal (standardized uptake value ratio) and analyzed with a mixed effect model. Secondary outcome measures included the change in Brief Pain Inventory, severity subscore. Among 60 enrolled participants, 48 completed the trial. Of these, 25 received minocycline (age [years], mean ± SD: 44.6 ± 16.9; 9 female), and 23 received placebo (49 ± 17.1; 9 female). The mean thalamic positron emission tomography standard uptake value ratio was very stable across visits in both groups, with no significant group-by-time interaction (P = 0.956). Similarly, both groups demonstrated a comparable decrease over time in Brief Pain Inventory severity scores (P = 0.018) and no significant group-by-time interaction (P = 0.329). Our results suggest that minocycline, at the tested regimen, may neither reduce brain TSPO levels nor have clinically meaningful effects on clinical pain in patients with cLBP.

Association between pain intensity and body composition in adults with chronic non-specific low back pain: A systematic review and meta-analysis

INTRODUCTION

This systematic review and meta-analysis evaluated the association between pain intensity and different body composition measures in adults suffering from chronic non-specific low back pain (CNLBP).

METHODS

A systematic literature search across five databases-PubMed, Embase, CINAHL, Web of Science, and the Cochrane Library-was conducted. It identified observational studies published until January 2024. A meta-analysis was conducted incorporating a random-effects approach with Fisher's Z transformation. A critical appraisal of the included studies' quality was conducted.

RESULTS

Twenty-two studies were included. Of those, 20 were meta-analyzed, revealing positive, very weak correlations between pain intensity and body mass index (r = 0.11; 95% CI: 0.04 to 0.18), waist-hip ratio (r = 0.10; 95% CI: -0.14 to 0.34) and waist circumference (r = 0.09; 95% CI: -0.28 to 0.44). Not pooled study findings (e.g., hip circumference and body fat percentage) were narratively summarized, revealing 13 positive and four negative associations between pain intensity and body composition measures. Studies showed a substantial risk of bias due to unadjusted confounding factors and limited transferability of findings.

CONCLUSION

This systematic review and meta-analysis provided very low-quality evidence for a positive, very weak association between pain intensity and body composition measures in adults with overweight and obesity suffering from CNLBP. The included studies had a substantial risk of bias due to their observational and cross-sectional study designs, which prevents recommendations for clinical practice. Randomized controlled trials are needed to investigate the causal effect of interventions on body composition measures and pain intensity.

The Efficacy and Safety of Botulinum Neurotoxin Type A in Treating Chronic Low Back Pain: A Systematic Review, Meta-Analysis, Trial Sequential Analysis, and Meta-Regression

BACKGROUND

Chronic low back pain (CLBP) is a leading cause of disability. Botulinum neurotoxin type A (BoNT-A) has strong anti-spasmodic and analgesic effects, suggesting that its local muscular injection can reduce CLBP compared to other therapies. In this systematic review and meta-analysis, we investigated the efficacy and safety of BoNT-A on patients with CLBP.

METHODS

We searched PubMed, Scopus, Cochrane, and Web of Science databases for studies comparing BoNT-A to other therapies in terms of functional improvement and pain improvement as measured by visual analog scale (VAS) and clinically significant improvement in pain (50% or greater reduction in VAS score). We employed trial sequential analysis (TSA) to confirm the findings. The GRADE approach was employed to assess the overall quality of the evidence.

RESULTS

The search yielded nine studies, seven randomised clinical trials (RCTs), and two prospective observational studies. Compared to the control, BoNT-A increased the incidence of clinically significant improvement in pain (RR = 4.82, 95% CI (3.00, 7.76), p < 0.00001) and functional improvement (RR = 3.81, 95% CI (2.40, 6.04), p < 0.00001) (low-certainty evidence), and reduced VAS score (MD = -1.62, 95% CI (-3.13, -0.11), p = 0.04) (very low-certainty evidence). Subgroup analysis showed that BoNT-A is effective against normal saline (moderate-certainty evidence), and it was comparable to steroids and local anaesthetics (very low-certainty evidence). TSA confirmed the findings regarding clinical improvement in pain and functional improvement.

CONCLUSION

BoNT-A is a tolerable and effective treatment for CLBP with a longer duration of action. Future high-quality studies are needed to confirm our findings.

SIGNIFICANCE

This paper provides good evidence that BoNT-A may be employed in patients suffering from resistant chronic low back pain not responding to normal saline injection due to its higher efficacy and longer duration of action. Compared to steroids and local anaesthetics injections, there is not enough data to draw a firm conclusion and future studies are needed.

State-of-the-Art Personalized Therapy Approaches for Chronic Non-Specific Low Back Pain: Understanding the Mechanisms and Drivers

Chronic non-specific low back pain (CNSLBP) is a debilitating condition that affects millions of people worldwide, significantly impacting quality of life and imposing a substantial socioeconomic burden. Traditional treatment approaches often rely on a one-size-fits-all strategy, failing to account for individual variations in pathophysiological mechanisms, drivers, and the principles of personalized medicine. Furthermore, an overemphasis on biomechanical findings from imaging may lead to ineffective interventions and unnecessary surgical procedures, obscuring other important factors that contribute to pain perception. While highlighting the limitations of universal treatment approaches, in this review we present a practical clinical approach aimed at elucidating the main pathophysiological mechanisms and various factors underlying the development and maintenance of CNSLBP in order to create a personalized treatment program. In conclusion, this review underscores the need for personalized therapeutic strategies that take into account the unique characteristics of each patient, recognizing the complex interaction of biological, psychological, social, and other factors that contribute to the development of individual pain. By combining a comprehensive understanding of the complexities of this condition, we aim to improve clinical outcomes and provide information on the development of effective personalized treatment algorithms, particularly in the field of neurological practice.

Measurement properties of the 5-repetition sit-to-stand test in patients with lumbar degenerative disorders: COSMIN systematic review

BACKGROUND CONTEXT

There has been no recent updated comprehensive review of measurement properties focused on the 5-repetition sit-to-stand test (5R-STS) in patients with lumbar degenerative disorders (LDD) that could aid in better understanding of its clinical and research applicability.

PURPOSE

The aim of this systematic review was to summarize evidence on measurement properties of the 5R-STS in patients with LDD according to COnsensus Based Standards for the Selection of Health Measurement INstruments (COSMIN) guidelines.

DESIGN

Systematic review and meta-analysis.

PATIENT SAMPLE

In Step 1 and 2, 3,363 and 1,287 adult patients with suspected or diagnosed either clinically and/or radiologically LDD were included, respectively. Step 2 involved screening studies from Step 1 that passed the full text-stage and including only those that assessed at least 1 COSMIN measurement property.

OUTCOME MEASURES

Functional Measures (5R-STS, Timed Up and Go Test). Self-report Measures (including Oswestry Disability Index (ODI), Roland Morris Disability Questionnaire, pain scores eg, Visual Analogue Scale) and healthcare quality of life questionnaires (eg, EQ-5D-3L)).

METHODS

In December 2022 Embase, PubMed/Medline, Web of Science and Scopus were searched for studies of 5R-STS of patients with LDD (PROSPERO: CRD42022383095). Quality of evidence was assessed using GRADE and COSMIN Checklist. Results for measurement error were pooled using the weighted mean method. Random effect meta-analysis was performed for studies on reliability and criterion validity.

RESULTS

Thirty-eight full-text articles were included in Step 1 and 19 in Step 2. The overall intraclass correlation coefficient (ICC) of test-retest reliability and inter-rater reliability of the 5R-STS was 0.93 (95% CI 0.37-1.00) and 0.99 (95% CI 0.83-1.00), respectively. The weighted standard error of measurement (SEM) mean value was 2.8s. Estimated r of 5R-STS and ODI, reflecting insufficient criterion validity (since r <0.70), was 0.53 (95% CI 0.17-0.88). Hypothesis testing for construct validity was confirmed for 40% of predefined hypothesis (graded as insufficient since overall, not >70% hypothesis confirmed). Accounting for limited evidence, responsiveness of the test was adequate.

CONCLUSION

This COSMIN systematic review summarizes 5R-STS measurement properties in patients with LDD, including pooled estimates of ICC for reliability, SEM, and correlation between 5R-STS and ODI. The 5R-STS is a reliable and responsive instrument reflecting a new dimension of functional impairment in patients with LDD.

Peak alpha frequency differs between chronic back pain and chronic widespread pain

BACKGROUND

Low peak alpha frequency (PAF) is an electroencephalography (EEG) outcome associated reliably with high acute pain sensitivity. However, existing research suggests that the relationship between PAF and chronic pain is more variable. This variability could be attributable to chronic pain groups typically being examined as homogenous populations, without consideration being given to potential diagnosis-specific differences. Indeed, while emerging work has compared individuals with chronic pain to healthy controls, no previous studies have examined differences in PAF between diagnoses or across chronic pain subtypes.

METHODS

To address this gap, we reanalysed a dataset of resting state EEG previously used to demonstrate a lack of difference in PAF between individuals with chronic pain and healthy controls. In this new analysis, we separated patients by diagnosis before comparing PAF across three subgroups: chronic widespread pain (n = 30), chronic back pain (n = 38), and healthy controls (n = 87).

RESULTS

We replicate the original finding of no significant difference between chronic pain groups and controls, but also find that individuals with widespread pain had significantly higher global average PAF values than those of people with chronic back pain [p = 0.028, β = 0.25 Hz] after controlling for age, sex, and depression.

CONCLUSIONS

These novel findings reveal PAF values in individuals with chronic pain may be diagnosis-specific and not uniformly shifted from the values of healthy controls. Future studies should account for diagnosis and be cautious with exploring homogenous 'chronic pain' classifications during investigations of PAF.

SIGNIFICANCE

Our work suggests that, contrary to previous hypotheses, inter-individual differences in PAF reflect diagnosis-specific mechanisms rather than the general presence of chronic pain, and therefore may have important implications for future work regarding individually-tailored pain management strategies.

Language errors in pain medicine: An umbrella review

Errors in language are common in pain medicine, but the extent of such errors has not been systematically measured. This pre-registered umbrella review explored Embase, PubMed, Medline and CINAHL and seeks to quantify the prevalence of errors in language in review articles since the last IASP definition revision. To be eligible, studies must have met the following criteria: 1) Primary aim was stated as to provide neurophysiological explanations of nociception and/or pain in humans in context of a pathology/condition; 2) Any type of review article; 3) Written in English; 4) Published in a peer-reviewed journal. Studies were excluded if they met any of the following criteria: 5) Published prior to the last revision of the IASP definition; 6) Published after May 2023; 7) Published in a predatory journal. Out of 5470 articles screened, 48 review articles met the inclusion criteria. All articles contained at least one error in language, there were no differences in the proportions of errors in language in review articles between years of publication, and various predictors were mostly not associated with a higher or lower number of errors in language counts in articles. Our findings reveal the need for heightened awareness among researchers, clinicians, journals and editorial boards regarding the prevalence and impact of these errors. Given our findings and their limitations, further research should focus on examining the contextual influence of misnomer usage and replication of these results. PERSPECTIVE: This umbrella review explored the main biomedical databases to see how many review articles contained language errors. Our findings underscore the imperative for prompt action in regulating pain medicine terminology. PRE-REGISTRATION: This umbrella review was pre-registered on OSF registries (https://doi.org/10.17605/osf.io/kau8m). ONLINE MATERIAL: https://osf.io/kdweg/.

Association of lumbar disc herniation and paraspinal muscles changes in patients with chronic low back pain

BACKGROUND

Patients with chronic low back pain (CLBP) exhibit changes in paraspinal muscles fat infiltration and cross-sectional area (CSA). However, the relationship between lumbar disc herniation (LDH) and paraspinal muscles changes in CLBP patients remains unclear.

OBJECTIVE

To analyze the relationship between LDH, fat infiltration in paraspinal muscles, and their CSA in patients with CLBP.

METHODS

A total of 494 patients (201 males and 293 females) with an average age of 45.75 ± 12.93 years with CLBP were included in this study. Conventional magnetic resonance scanning sequences, inverted phase and Iterative Decomposition of water and fat with the Echo Asymmetry and Least-Square Estimation quantitation (IDEAL-IQ) sequences were used, and patients were assessed for pain on a visual analog scale (VAS). LDH was assessed based on T2 axial images at the L4-S1 level. Multifidus and erector spinae CSA and proton density fat fraction (PDFF) were measured bilaterally at the central level of the L4-S1 disc using the above-mentioned sequences and normalized by the square of height.

RESULTS

Patients with LDH had a higher PDFF of the paraspinal muscles at the L4/5 level compared to those without LDH (p < 0.05). Additionally, the VAS score of patients with LDH was significantly higher than that of the control group (p < 0.05). However, there was no significant difference in the change of paraspinal muscles CSA between patients with CLBP with and without LDH.

CONCLUSION

In patients with LDH, there is increased fatty infiltration in the paraspinal muscles, with no significant changes in CSA. Different types of LDH are not related to paraspinal muscles fatty infiltration and CSA.

Effects of whole-body vibration therapy on pain, functionality, postural stability, and proprioception in patients with subacute and chronic non-specific low back pain: a systematic review

INTRODUCTION

Non-specific low back pain (NLBP) is a common and clinically significant condition with substantial socioeconomic implications. Whole-body vibration therapy (WBVT) has shown effectiveness in improving pain and sensorimotor function (e.g., in osteoporosis) in previous studies. However, studies had heterogeneous settings. The aim of this study was to assess the effects of WBVT on pain, function, proprioception, and postural stability in patients with subacute and chronic NLBP.

METHODS

A systematic literature search was conducted in the scientific databases PubMed, EMBASE, and PEDro (from inception until 17.05.2023). Only prospective controlled and uncontrolled studies were included. Outcome measures assessed were pain intensity, function (activities of daily living and physical function), proprioception, and postural stability.

RESULTS

A total of 12 original articles (n = 821) were included in the analysis. Ten of the studies were randomized controlled trials, one study had a crossover design, and one study had a one-group pre-post study design. The studies compared WBVT vs. no intervention, WBVT vs. basic physical therapy, WBVT vs. core stabilization exercises with and without respiratory resistance, WBVT vs. lumbar extension exercises, and WBVT vs. whole body electromyostimulation training. The treatment approaches varied in terms of duration (2-18 weeks), frequency (2-3 times per week, two applications with a 2-week break), vibration frequency (5-30 Hz), type of exercises (WBVT with or without static or dynamic exercises), and vibration direction (horizontal and vertical). Significant pain reduction was observed in all 10 studies that investigated pain levels. Significant improvement in daily activity function was reported in five of the six studies that investigated daily function, while improvement in physical function was observed in all four studies that investigated physical function. Improvement in proprioception was reported in all three studies that investigated proprioception, and significant improvement in postural stability was observed in four out of six studies that investigated postural stability. No adverse events or side effects related to WBVT were reported.

CONCLUSION

The majority of the included studies demonstrated significant pain reduction, improvement in physical and daily functioning, and enhanced proprioception. Improvement in postural stability was less consistent. WBVT appears to be a safe and effective treatment modality for subacute and chronic NLBP when used within a multimodal approach. Future research should focus on standardized settings including assessment methods, treatment regimens, frequencies, and intensities.

Is the Central Sensitization in Chronic Nonspecific Low Back Pain Structural Phenomenon or Psychological Reaction? A Narrative Review

Lower back pain (LBP) is a common condition affecting primarily populations in developed countries, placing a significant burden on public health systems around the world. A high rate of pain recurrence increases the risk of developing a chronic syndrome and the occurrence of complex psychosocial and professional problems. Symptoms lasting longer than 12 weeks are associated with the risk of sleep problems, depression, and anxiety. In the 21st century, the development of knowledge about central sensitization (CS) to pain allowed for a better understanding of the pathomechanism of pain and the transformation of LBP into a chronic form. Patients with chronic severe pain often experience accompanying symptoms such as fatigue, depression, anxiety, sleep disorders, appetite disorders, flatulence, dyspepsia, and dizziness-these are part of the picture of CS. The article presents a narrative, chronological review of reports covering the current state of knowledge on the possibility of assessing central sensitization and its impact on low back pain. The authors also attempt to answer the question posed in the title. CS can be seen as an excessive reactivity of nociceptive neurons in the central nervous system to normal or subthreshold afferent chronic stimuli in people with certain mental predispositions.

Efficacy and safety evaluation of Boswellia serrata and Curcuma longa extract combination in the management of chronic lower back pain: A randomised, double-blind, placebo-controlled clinical study

BACKGROUND AND AIM

Chronic lower back pain (CLBP) is a major condition that leads to disability and reduced quality of life (QoL). This randomised, double-blind, placebo-controlled clinical study evaluated the efficacy and safety of a novel Boswellia serrata and Curcuma longa combination (CL20192) for the treatment of CLBP.

MATERIAL AND METHODS

Participants with CLBP were randomised to receive either a 300 mg CL20192 capsule (n = 45) or placebo capsule (n = 45) once daily for 90 days. Efficacy was evaluated using the Descriptor Differential Scale and Oswestry Disability Index scores for pain, unpleasantness, and disability. Additionally, the 36-item short form questionnaire was used for QoL evaluation. Frequency of painkiller use, serum levels of inflammatory biomarkers (tumour necrosis factor-α, interleukin-6, and high-sensitivity C-reactive protein), and phytoconstituents (total boswellic acids and curcuminoids) were determined. Therapy satisfaction was assessed using the Physician and Patient Global Assessment Scales.

RESULTS

All randomised participants completed the study. CL20192 supplementation significantly reduced Descriptor Differential Scale pain, unpleasantness, and Oswestry Disability Index scores compared with the placebo group (p < 0.001 for all parameters). Critical QoL scores greatly improved in the CL20192 group. Serum phytoconstituent levels were elevated in the CL20192-treated group. This group demonstrated a significant reduction in inflammatory biomarker levels (tumour necrosis factor-α, interleukin-6, and high-sensitivity C-reactive protein), confirming efficacy in abating CLBP compared with the placebo. Moreover, therapy satisfaction scores were significantly high in the CL20192-treated group, and intervention with CL20192 was well tolerated.

CONCLUSION

Intervention with 300 mg CL20192 capsules, containing a novel combination of Boswellia serrata and Curcuma longa extracts, effectively alleviated pain, unpleasantness, and disability in patients with CLBP compared with the placebo. This outcome was consistent with a decrease in serum inflammatory markers and improved therapy assessment scores.

The Clinical Status of Patients With Lumbar Spinal Stenosis Reflects Their Individual Decision to Undergo or Defer Lumbar Spinal Surgery

OBJECTIVE

To evaluate whether functional, clinical, and self-reported tests reflect lumbar spinal stenosis patients' decisions to undergo or defer surgery.

METHODS

Among 108 participants, 77 chose surgery (SG), and 31 opted to wait and see (WaSG) whether they got better spontaneously. Both groups were assessed at baseline (t0) and 3 months (t1), with additional self-reported measures at 6 (t2) and 12 months (t3). Key outcomes included corridor walk distance, chair sit-to-stand repetitions, grip strength, and various pain and disability indices.

RESULTS

At baseline, SG reported higher leg pain (NPRS-leg: Δ = 1.66, P = 0.002) and poorer functional outcomes across multiple tests. By t1, both groups improved in disability, but SG showed greater reductions in the Oswestry Disability Index (Δ = 7.85, P = 0.001) and sustained improvements in leg pain at subsequent assessments. WaSG consistently engaged in more walking (mean Δ = 123.5 minutes, P < 0.001). Regression analyses indicated that surgery status, flexibility, and strength significantly predicted improvements in disability (adjusted R² = 0.296). Logistic regression identified predictors for surgery choice, including biological sex, leg pain intensity, walking performance, and weekly walking hours.

CONCLUSION

Functional status, self-reported disability, and fear-avoidance beliefs in lumbar spinal stenosis patients reflect their subjective decision regarding surgery and highlight the importance of baseline leg pain, calf strength, walking-related parameters, and physical function in recovery.

STUDY DESIGN

Observational prospective cohort.

Multimodal intervention based on physical exercise, mindfulness, behaviour change and education to improve pain and health in patients with chronic primary low back pain: a study protocol of the HEALTHYBACK randomised controlled trial

The HEALTHYBACK trial is based on a multimodal intervention to determine the effectiveness of a supervised physical exercise, mindfulness, behaviour change and pain neuroscience education programme on several health variables in individuals with chronic primary low back pain (CPLBP). The study will be a randomised controlled trial among 70 individuals diagnosed with CPLBP (aged 18-65 years). The intervention will be conducted in person within a hospital setting for 16 weeks and comprises a first phase (16 sessions supervised physical exercise (2 days/week, 45 min/session), mindfulness (1 day/week, 2.5 hours/session), behaviour change (daily/24 hours via a wrist-worn activity prompting device) and pain neuroscience education (1 day/biweekly, 2 hours/session)) and a second phase (16 sessions functional full-body muscle strengthening exercise, 3 days/week, 50 min/session). The primary outcomes will include perceived acute pain, pain pressure threshold, conditioned pain modulation, temporal summation of pain and disability due to pain. Secondary measures will include physical fitness, body composition, gait parameters, device-measured physical activity and sedentary behaviour, haematological profile, self-reported sedentary behaviour, quality of life, pain catastrophising, mental health, sleep duration and quality, and symptoms related to central sensitisation. The groups will undergo pretest (before the intervention), post-test (after each phase of the intervention) and retest (at a 6-week detraining period after the intervention) measurements. The results will determine the effectiveness of multidimensional interventions on several health parameters in individuals with CPLBP. They will provide knowledge for pain management and functioning in affected individuals, which might diminish the need for primary healthcare services. Trial registration number: NCT06114264.

Neuroplastic Responses to Chiropractic Care: Broad Impacts on Pain, Mood, Sleep, and Quality of Life

OBJECTIVES

This study aimed to elucidate the mechanisms of chiropractic care using resting electroencephalography (EEG), somatosensory evoked potentials (SEPs), clinical health assessments (Fitbit), and Patient-reported Outcomes Measurement Information System (PROMIS-29).

METHODS

Seventy-six people with chronic low back pain (mean age ± SD: 45 ± 11 years, 33 female) were randomised into control (n = 38) and chiropractic (n = 38) groups. EEG and SEPs were collected pre and post the first intervention and post 4 weeks of intervention. PROMIS-29 was measured pre and post 4 weeks. Fitbit data were recorded continuously.

RESULTS

Spectral analysis of resting EEG showed a significant increase in Theta, Alpha and Beta, and a significant decrease in Delta power in the chiropractic group post intervention. Source localisation revealed a significant increase in Alpha activity within the Default Mode Network (DMN) post intervention and post 4 weeks. A significant decrease in N30 SEP peak amplitude post intervention and post 4 weeks was found in the chiropractic group. Source localisation demonstrated significant changes in Alpha and Beta power within the DMN post-intervention and post 4 weeks. Significant improvements in light sleep stage were observed in the chiropractic group along with enhanced overall quality of life post 4 weeks, including significant reductions in anxiety, depression, fatigue, and pain.

CONCLUSIONS

These findings indicate that many health benefits of chiropractic care are due to altered brain activity.

Job stress and chronic low back pain: incidence, number of episodes, and severity in a 4-year follow-up of the ELSA-Brasil Musculoskeletal cohort

ABSTRACT

We investigated the association between job stress, as assessed by the effort-reward imbalance model, and the incidence of chronic low back pain (CLBP) over a 4-year period. A total of 1733 participants from the ELSA-Brasil Musculoskeletal cohort, who were free from LBP at baseline (2012-2014), were included. Episodes of LBP in the past 30 days, intensity, and the presence of disability were investigated in annual telephone follow-ups (2015-2018). Chronic LBP was defined as episodes of LBP lasting >3 months with at least moderate intensity. We analyzed the incidence of at least one episode of CLBP (yes/no), the number of CLBP episodes (0, 1, ≥2), and CLBP severity/disability (absent, nondisabling, severe/disabling). The association between these outcomes and tertiles of the effort-to-reward ratio, as well as each dimension of the effort-reward imbalance model, was investigated using multinomial logistic and Poisson regression models adjusting for sociodemographic and occupational variables. The cumulative incidence of CLBP over 4 years was 24.8%. High effort-reward imbalance increased the chances of experiencing multiple CLBP episodes and severe/disabling CLBP by 67% (95% confidence interval [CI]: 1.12-2.47) and 70% (95% CI: 1.14-2.53), respectively. High overcommitment increased the incidence of CLBP by 23% (95% CI: 1.01-1.50) and the chances of multiple CLBP episodes and severe/disabling CLBP by 67% (95% CI: 1.11-2.50) and 57% (95% CI: 1.05-2.34), respectively. These results indicate that exposure to job stress is associated with a higher incidence, a greater number of episodes, and increased severity of CLBP over a 4-year period. If this association is causal, measures aimed at reducing exposure to job stress are likely to alleviate the burden of CLBP.

Patients' experiences with the application of medical adhesives to the skin: a qualitative systematic review

OBJECTIVES

Medical adhesives provide securement of medical devices, facilitate skin protection and allow non-invasive monitoring. Application and removal of medical adhesives can result in pain, dermatitis, trauma or other skin lesions. Understanding patients' experiences when subjected to medical adhesives will contribute to the improvement of clinical routines and the development and improvement of new adhesive technologies. A qualitative systematic review was conducted to identify patients' experiences with the application of medical adhesives to the skin.

DESIGN

Qualitative systematic review.

DATA SOURCES

CINAHL, EMBASE, MEDLINE and PsycINFO were systematically searched for records published between January 2012 and March 2024. Reference lists of systematic reviews and included articles were reviewed.

ELIGIBILITY CRITERIA

Studies published in Danish, Dutch, English, German, Norwegian and Swedish that collected qualitative data on the experience of patients with the application of medical adhesives to the skin were considered. There were no restrictions regarding age, gender or setting.

DATA EXTRACTION AND SYNTHESIS

Study selection, data extraction and quality appraisal were independently conducted by two reviewers. The methodological quality of the studies under consideration was assessed using the Joanna Briggs Institute Critical Appraisal Tool for Qualitative Research. The extracted data were synthesised using meta-aggregation.

RESULTS

Nine studies describing patients' experiences were included. The included studies only reflected experiences with wound dressings. Meta-aggregation of the extracted findings resulted in seven categories that were further synthesised into two synthesised findings: 'strategies to alleviate pain during dressing changes' and 'dressing construction and characteristics'. The synthesised findings illustrate that patients experience pain during dressing change and removal and employ various strategies to alleviate this pain.

CONCLUSIONS

Patients experience pain and discomfort when dressings are changed or removed. Future research should focus on enhancing both routines and technologies, with a particular emphasis on advancing skin-friendly adhesives to reduce unwanted side effects.

PROSPERO REGISTRATION NUMBER

CRD42023457711.

Electroacupuncture at Traditional Acupoints or Myofascial Trigger Points for Chronic Nonspecific Low Back Pain: High or Alternated Frequency? A Double-Blinded Randomized Controlled Trial

Background

Chronic nonspecific low back pain (cNLBP) can be effectively treated by electroacupuncture (EA) at traditional acupoints (TAPs) and myofascial trigger points (MTrPs). However, the optimal type and frequency of stimulation (alternated frequency [AF] and high frequency [HF]) remain unclear. This study aimed to explore this.

Methods

A double-blinded randomized controlled trial was conducted with four treatment groups: EA using AF at MTrPs (MTP-AF group), HF at MTrPs (MTP-HF group), AF at TAPs (TAP-AF group), and HF at TAPs (TAP-HF), each with 40 middle-aged cNLBP patients. The AF was 2/100 Hz and HF was 100 Hz. Pain-visual analog scale (pain-VAS), paracetamol requirement, Oswestry disability index (ODI) score, global improvement, and adverse effects (AEs) were monitored.

Results

After 4 weeks, groups of EA targeting MTrPs and TAPs with the same frequency showed no significant differences. Groups using AF demonstrated significantly superior pain-VAS and ODI percentage score reductions compared with HF groups, extending at least 4 weeks post-EA. All groups showed consistent results in paracetamol use, global improvement, and safety. Subgroup analysis indicated that EA with AF at MTrPs provided better results in patients aged ≥60-65 years.

Conclusions

EA at MTrPs and TAPs demonstrated similar effects on cNLBP. However, an AF proves more effective than an HF, potentially maintaining this trend in the short term. Older patients may respond better to EA at MTrPs with AF. Future studies may explore combined MTrPs and TAPs for cNBLP treatment with a broader age range and more diverse demographic groups.

Biomolecular therapies for chronic discogenic low back pain: A narrative review

Chronic low back pain caused by intervertebral disc (IVD) degeneration, also termed chronic discogenic low back pain (CD-LBP), is one of the most prevalent musculoskeletal diseases. Degenerative processes in the IVD, such as inflammation and extra-cellular matrix breakdown, result in neurotrophin release. Local elevated neurotrophin levels will stimulate sprouting and innervation of sensory neurons. Furthermore, sprouted sensory nerves that are directly connected to adjacent dorsal root ganglia have shown to increase microglia activation, contributing to the maintenance and chronification of pain. Current pain treatments have shown to be insufficient or inadequate for long-term usage. Furthermore, most therapeutic approaches aimed to target the underlying pathogenesis of disc degeneration focus on repair and regeneration and neglect chronic pain. How biomolecular therapies influence the degenerative IVD environment, pain signaling cascades, and innervation and excitability of the sensory neurons often remains unclear. This review addresses the relatively underexplored area of chronic pain treatment for CD-LBP and summarizes effects of therapies aimed for CD-LBP with special emphasis on chronic pain. Approaches based on blocking pro-inflammatory mediators or neurotrophin activity have been shown to hamper neuronal ingrowth into the disc. Furthermore, the tissue regenerative and neuro inhibitory properties of extracellular matrix components or transplanted mesenchymal stem cells are potentially interesting biomolecular approaches to not only block IVD degeneration but also impede pain sensitization. At present, most biomolecular therapies are based on acute IVD degeneration models and thus do not reflect the real clinical chronic pain situation in CD-LBP patients. Future studies should aim at investigating the effects of therapeutic interventions applied in chronic degenerated discs containing established sensory nerve ingrowth. The in-depth understanding of the ramifications from biomolecular therapies on pain (chronification) pathways and pain relief in CD-LBP could help narrow the gap between the pre-clinical bench and clinical bedside for novel CD-LBP therapeutics and optimize pain treatment.

The Combined Effect Between Sleep Disorders and Depression Symptoms on Chronic Low Back Pain: A Cross-Sectional Study of NHANES

Purpose

To explore the combined effects of sleep disorders and depression on chronic low back pain (CLBP) in American adults.

Material and methods

In this cross-sectional study, the data of all participants were obtained from the National Health and Nutrition Examination Survey (NAHNES) between 2009 and 2010. CLBP was defined as persistent LBP for a consecutive three-month period. Sleep disorders were self-reported and were diagnosed by a doctor before. The Patient Health Questionnaire-9 (PHQ-9) was used to assess depressive symptoms by trained personnel. Potential covariates were selected using weighted univariate logistic regression models. Weighted univariate and multivariate logistic regression models were used to evaluate the separate and combined effects of sleep disorders and depression on CLBP, respectively. Results were presented as odds ratios (ORs) and 95% confidence intervals (CIs). Associations were further explored in the subgroups of age, chronic kidney disease (CKD), diabetes, and having pain outside the low back.

Results

A total of 5275 participants were included. Among them, 542 (10.28%) had CLBP. The mean age of all participants was 47.19 (0.53), and 50.65% (n=2668) were female. Sleep disorder (OR=1.52, 95% CI: 1.17-1.98) or depressive symptoms (OR=3.06, 95% CI: 2.41-3.88) were associated with higher odds of CLBP. Compared to participants without sleep disorders and depression symptoms, participants in both conditions had an increased risk of CLBP (OR=3.95, 95% CI: 2.58-6.05, P for trend <0.001). The combined effects of sleep disorders and depressive symptoms were also found in the population aged <45 years, ≥45 years, with and without CKD, with and without diabetes, and no pain outside the low back.

Conclusion

Sleep disorders and depressive symptoms may increase the odds of reporting CLBP. Further research is necessary to explore the effectiveness of multidisciplinary interventions targeting sleep disorders, depressive symptoms, and CLBP.

Association between vertebral endplate defects and patient-reported symptoms: an immunohistochemical study investigating the COX-2/PGE-2/EP-4 axis

BACKGROUND CONTEXT

Vertebral endplate defects are often implicated in degenerative disc disorders, yet their connection to patient-reported symptoms remains unclear. COX-2 and PGE-2 are known for their roles in inflammation and pain, with EP-4 receptor involvement in pain signaling. Examining their expression in vertebral endplate tissues may provide insights into pathomechanism of low back pain.

PURPOSE

To investigate the association between endplate defects and patient-reported symptoms and to further clarify the role of the COX-2/PGE-2/EP-4 axis in the pathogenesis of chronic low back pain.

STUDY DESIGN/SETTING

Retrospective study.

PATIENT SAMPLE

A total of 71 patients who had undergone single-level L4/5 or L5/S1 modified laminectomy decompression preserving proximal upper laminae and transforaminal lumbar interbody fusion surgery were included in this study, including 18 patients diagnosed with lumbar disc herniation, 19 with lumbar disc herniation accompanied by degenerative lumbar spinal stenosis, and 34 with degenerative spondylolisthesis.

OUTCOME MEASURES

Demographic data, Pfirrmann grade, Modic changes, endplate defect score, visual analog scale (VAS) for back and leg pain, and Oswestry Disability Index (ODI) before surgery, 3-month and 6-month follow-up, and the percentage of immune-positive cells (COX-2, PGE-2, and EP-4) in endplate tissue sections.

METHODS

Patients were divided into defect and nondefect groups according to endplate morphology on lumbar MR. All intraoperative endplate specimens were immediately fixed in 10% formaldehyde, and then embedded in paraffin 3 days later for tissue sections. The outcome measures were compared between the defect group and nondefect group. Data were analyzed using independent t-tests and χ² tests. Pearson's rank correlation test was used to assess correlations between patient-reported symptoms and the percentage of immune-positive cells in the groups. Multivariable logistic regression models using the forward stepwise likelihood ratio method were used to identify the factors that were independently associated with endplate defects.

RESULTS

The age of Defect group was significantly higher than that of nondefect group (52.5±7.7 vs 57.2±9.1. p=.024). There were no significant differences in gender, diagnosis, BMI, comorbidities, or surgical level between the two groups. Modic changes (Type Ⅱ/Type Ⅲ) were more common in patients of Defect group than nondefect group (38.5% vs 11.1%, p<.001), and so was disc degeneration (Pfirrmann grade Ⅳ/Ⅴ) (69.2% vs 33.3%, p<.001). Defect group had significantly higher VAS-Back (6.5±2.0 vs 4.9±1.6, p<.001) and ODI scores (62.9±10.7 vs 45.2±14.8, p<.001) than nondefect group, while there was no significant differences between the two groups during the 3 and 6-month follow-up after surgery. Histologically, Defect group was characterized by upregulation of COX-2, PGE-2, and EP-4 in endplate tissue sections. Both in defect and nondefect groups, VAS-Back showed moderate positive correlations with the expressions of COX-2 (r=0.643; r=0.558, p both<.001), PGE-2 (r=0.611; r=0.640, p both<.001), and EP-4 (r=0.643; r=0.563, p both<.001). Multivariate regression analyses reveled that percentage of COX-2-positive cells was associated with endplate defects (OR=1.509, 95%CI [1.048-2.171], p=.027), as well as percentage of PGE-2-positive (OR=1.291, 95%CI [1.106-1.508], p=.001) and EP-4-positive cells (OR=1.284, 95%CI [1.048∼2.171], p=.003).

CONCLUSIONS

Patients with endplate defects had worse quality of life, more severe disc degeneration and Modic changes, and up-regulated COX-2/PGE-2/EP-4 axis expression in cartilage endplates in patients with defected endplates. Inflammatory factors may significantly contribute to the onset and progression of chronic low back pain in patients with endplate defects, consequently impacting patient-reported symptoms.

Exercise-induced neuroplasticity: a new perspective on rehabilitation for chronic low back pain

Chronic low back pain patients often experience recurrent episodes due to various peripheral and central factors, leading to physical and mental impairments, affecting their daily life and work, and increasing the healthcare burden. With the continuous advancement of neuropathological research, changes in brain structure and function in chronic low back pain patients have been revealed. Neuroplasticity is an important mechanism of self-regulation in the brain and plays a key role in neural injury repair. Targeting neuroplasticity and regulating the central nervous system to improve functional impairments has become a research focus in rehabilitation medicine. Recent studies have shown that exercise can have beneficial effects on the body, such as improving cognition, combating depression, and enhancing athletic performance. Exercise-induced neuroplasticity may be a potential mechanism through which exercise affects the brain. This article systematically introduces the theory of exercise-induced neuroplasticity, explores the central effects mechanism of exercise on patients with chronic low back pain, and further looks forward to new directions in targeted neuroplasticity-based rehabilitation treatment for chronic low back pain.

Psychometric properties of the Turkish version of Central Sensitization Inventory-9 in patients with chronic musculoskeletal pain

The aim of the study was to assess the psychometric properties of the Turkish version of Central Sensitization Inventory-9 (CSI-9) in patients with chronic musculoskeletal pain. The methodological study included 92 patients with chronic musculoskeletal pain. The original version of the CSI-9 was translated and culturally adapted into Turkish. The internal consistency and test-retest reliability were evaluated with Cronbach's α and the intraclass correlation coefficient (ICC), respectively. The assessment of reproducibility was conducted with the standard error of measurement (SEM) and minimal detectable difference (MDD) values. Convergent validity was explored by correlation analysis between the CSI-9 and Central Sensitization Inventory (CSI-25), Brief Pain Inventory (BPI), and European Quality of Life Survey-5 Dimensions (EQ-5D). The structural validity was assessed with factor analysis. Floor and ceiling effects were also analyzed. We found a very good internal consistency (Cronbach's α of 0.83) and excellent test-retest reliability (ICC of 0.96) of the Turkish CSI-9. The SEM demonstrated a range between 0.19 and 1.12, and the MDD was observed to vary from 1.17 to 1.35. The CSI-9 correlated significantly with the CSI-25 ( r  = 0.77, P  < 0.001), the pain severity subscale of the BPI ( r  = 0.41 to 0.53, P  < 0.001), the pain interference subscale of the BPI ( r  = 0.21 to 0.58, P  = 0.02 to P  < 0.001), the EQ-5D ( r  = 0.24 to 0.48, P  < 0.05), and the EQ-5D visual analog scale ( r  = -0.41, P  < 0.001). One factor was identified within the CSI-9. Our data suggest that the Turkish CSI-9 is reliable and valid outcome measure for assessing CS in patients with chronic musculoskeletal pain.

Analysis of lumbar spine loading during walking in patients with chronic low back pain and healthy controls: An OpenSim-Based study

Low back pain (LBP) is one of the most prevalent and disabling disease worldwide. However, the specific biomechanical changes due to LBP are still controversial. The purpose of this study was to estimate the lumbar and lower limb kinematics, lumbar moments and loads, muscle forces and activation during walking in healthy adults and LBP. A total of 18 healthy controls and 19 patients with chronic LBP were tested for walking at a comfortable speed. The kinematic and dynamic data of the subjects were collected by 3D motion capture system and force plates respectively, and then the motion simulation was performed by OpenSim. The OpenSim musculoskeletal model was used to calculate lumbar, hip, knee and ankle joint angle variations, lumbar moments and loads, muscle forces and activation of eight major lumbar muscles. In our results, significant lower lumbar axial rotation angle, lumbar flexion/extension and axial rotation moments, as well as the muscle forces of the four muscles and muscle activation of two muscles were found in patients with LBP than those of the healthy controls (p < 0.05). This study may help providing theoretical support for the evaluation and rehabilitation treatment intervention of patients with LBP.

Retrospective review of the efficacy for sublingual ketamine in the treatment of chronic low back pain defined by a cause and central functional pain symptom focused clinical model

PURPOSE

Chronic low back pain is a leading cause of disability worldwide. A clinical model for its cause is lacking. Defining a cause based clinical model and a framework of understanding back pain in terms of peripheral structural and central functional pain is essential for optimal management.

MATERIALS AND METHODS

We describe the results of the largest published audit of 41 chronic low back pain patients, receiving outpatient sublingual ketamine therapy for defined central functional pain along with conventional peripheral structural pain management. Our clinical model assigns Movement Dysfunction as the primary cause for low back pain symptoms and restores it with Movement Therapy focused rehabilitation which is also defined. Patients were derived from a tertiary single neurosurgical specialist practice in Brisbane Australia over a three year period.

RESULTS

Severe pain and disability measurements more than halved and only 13% of patients ceased ketamine prematurely due to predominantly non-sinister side effects common to all pharmaceutical therapies. All other surveyed metrics of utility were highly favourable in this challenging cohort of chronic back pain patients biased to poor outcomes.

CONCLUSIONS

Outpatient ketamine maintains high efficacy and safety used in conjunction with a unique clinical model that describes chronic low back pain.

Predictive value of S100B and brain derived neurotrophic factor for radiofrequency treatment of lumbar disc prolapse

BACKGROUND

This work aimed to analyze serum S100B levels and brain-derived neurotrophic factor (BDNF) in patients with lumbar disc prolapse to test their predictive values concerning the therapeutic efficacy of pulsed radiofrequency.

METHODS

This prospective interventional study was carried out on 50 patients candidates for radiofrequency for treating symptomatic lumbar disc prolapse. Pain severity and functional disability were assessed using the Numeric Rating Scale (NRS) and Functional rating index (FRI) before as well as two weeks, 1, 3, and 6 months after the radiofrequency. Quantitative assessment of serum S100B level and BDNF was done for all the included patients one day before radiofrequency.

RESULTS

The scores of NRS and FRI were significantly improved at two weeks, 1, 3, and 6 months following radiofrequency (P-value < 0.001 in all comparisons). Statistically significant positive correlations were found between duration of pain, NRS, and S100B serum level before radiofrequency, and both NRS (P-value = 0.001, 0.035, < 0.001 respectively) and FRI (P-value = < 0.001, 0.009, 0.001 respectively) 6 months following radiofrequency. Whereas there were statistically significant negative correlations between BDNF serum level before radiofrequency and both NRS and FRI 6 months following radiofrequency (P-value = 0.022, 0.041 respectively). NRS and S100B serum levels before radiofrequency were found to be independent predictors of NRS 6 months following radiofrequency (P-value = 0.040. <0.001, respectively).

CONCLUSION

Serum level of S100B is a promising biomarker that can predict functional outcomes after pulsed radiofrequency in patients with lumbar disc prolapse.

Development and feasibility of a mindfulness-based dance/movement therapy intervention for chronic low back pain

Introduction

Responding to the need for innovative, multi-modal, non-pharmacological strategies in chronic low back pain (cLBP) care, this article presents the development and a mixed methods feasibility trial of a manualized Mindfulness-based Dance/Movement Therapy (M-DMT) program for cLBP. The 12-week program is designed as a group therapy, integrating mindfulness principles, creative/expressive dance and movement, and psychoeducational content focused on cLBP management. This holistic program seeks to cultivate nonjudgmental awareness of pain experiences, challenge maladaptive pain-related beliefs, enhance emotional well-being, foster social support, and promote effective coping strategies for the daily challenges associated with cLBP.

Methods

The 12-week M-DMT intervention was administered to individuals with non-specific cLBP (N = 18, aged 51.7 ± 13.9 years, 72% female, 55% Black and 39% White). We assessed feasibility and acceptability through monitoring enrollment and retention rates, attendance, and adverse events. Moreover, we measured the intervention's credibility/expectancy, participants' perception of changes, and overall satisfaction. Additionally, we collected qualitative data, capturing participants' perspectives on the intervention's usefulness and perceived benefits. Specific benchmarks were established to gauge the successful feasibility and acceptability of the program.

Results

The adherence rate stood at 80%, with a perfect retention rate of 100%. The study successfully met the benchmarks for treatment acceptability and satisfaction criteria, with 61% of participants reporting "feeling better" or a "great deal better" after the intervention. No adverse events were observed. Participants found the intervention enjoyable and reported that it provided effective tools for cLBP and related symptoms. Notably, participants reported a decrease in fear-avoidance behaviors, increased motivation for physical activity, and a boost in self-efficacy for pain management.

Discussion

These encouraging findings establish a strong basis for considering the M-DMT intervention as a promising approach for cLBP management, warranting further investigation in larger-scale studies.

An Integrated Approach to Chronic Low Back Pain: Evaluating the Impact of Consecutive Loop TheraBand Training Combined With Proprioceptive Neuromuscular Facilitation and Conventional Physiotherapy

Chronic low back pain (CLBP) is a prevalent musculoskeletal condition characterized by persistent discomfort in the lumbosacral region lasting beyond 12 weeks. Individuals with CLBP often experience limitations in range of motion and compromised performance of affected body parts. Core muscle weakness/delayed activation and impaired lumbar proprioception are established contributors to CLBP. And influence balance dysfunction in CLBP patients. Exercise therapy is a cornerstone in the management of CLBP, aimed at enhancing muscular endurance, strength, and flexibility of the back muscles and soft tissues. However, the efficacy of exercise interventions depends on various factors including the type, intensity, frequency, and duration of exercises. This case report presents the rehabilitation of a corporate employee with a non-specific CLBP. The rehabilitation goals focused on improving balance, reducing disability, and alleviating pain. An integrated approach combining proprioceptive neuromuscular facilitation (PNF) with Consecutive Loop TheraBand (CLX) (The Hygenic Corporation, Akron, USA) along with traditional physical therapy techniques was implemented. PNF, a well-established technique, was chosen for its effectiveness in reducing disability and LBP while enhancing balance. The integration of PNF alongside conventional physiotherapy resulted in notable improvements, including increased lumbar flexion range following the rehabilitation period. This case underscores the importance of early initiation of comprehensive rehabilitation in CLBP patients to preserve strength, alleviate pain, reduce functional disability, and enhance balance. By addressing both the muscular and proprioceptive aspects of CLBP, this integrated approach aims to optimize outcomes in CLBP management.

The associations between lumbar proprioception and postural control during and after calf vibration in people with and without chronic low back pain

The relationships of lumbar proprioception with postural control have not been clarified in people with chronic low back pain. This study aimed to compare the associations between lumbar proprioception and postural control in response to calf vibration in individuals with and without chronic low back pain. In this study, we recruited twenty patients with chronic low back pain (CLBP group) and twenty healthy control subjects (HC group) aged between 18 and 50 years. This study was a cross-sectional study and completed from May 2022 to October 2022. The passive joint repositioning sense (PJRS) test for two positions (15° and 35°) were used to assess lumbar proprioception and expressed as the mean of reposition error (RE). Postural control was tested by adding and removing calf vibration while standing on a stable force plate with eyes closed. The sway velocity in the anterior-posterior (AP) direction of center of pressure (COP) data with a window of 15s epoch at baseline, during and after calf vibration was used to evaluate postural control. Mann-Whitney U-tests were used to compare the difference of lumbar proprioception between two groups, and the independent t-tests were used to compare the difference of postural control at baseline and during vibration, and a mixed design ANOVA was used to compare the difference of postural control during post-perturbation. In addition, to explore the association between postural control and lumbar proprioception and pain intensity, Spearman's correlations were used for each group. The major results are: (1) significantly higher PJRS on RE of 15° (CLBP: 95% CI [2.03, 3.70]; HC: 95% CI [1.03, 1.93]) and PJRS on RE of 35° (CLBP: 95% CI [2.59, 4.88]; HC: 95% CI [1.07, 3.00]) were found in the CLBP group; (2) AP velocity was not different between the CLBP group and the HC group at baseline and during calf vibration. However, AP velocity was significantly larger in the CLBP group compared with the HC group at epoch 2-14 after calf vibration, and AP velocity for the CLBP group took a longer time (23 epochs) to return to the baseline after calf vibration compared with the HC group (9 epochs); (3) lumbar proprioception represented by PJRS on RE of 15°correlated negatively with AP velocity during and after vibration for the HC group. Within the CLBP group, no significant relationships between PJRS on RE for two positions (15° and 35°) and AP velocity in any postural phases were found. In conclusion, the CLBP group has poorer lumbar proprioception, slower proprioceptive reweighting and impaired postural control after calf vibration compared to the HC group. Lumbar proprioception offers different information on the control strategy of standing control for individuals with and without CLBP in the situations with proprioceptive disturbance. These results highlight the significance of assessing lumbar proprioception and postural control in CLBP patients.

Kinesiophobia, limits of stability, and functional balance assessment in geriatric patients with chronic low back pain and osteoporosis: a comprehensive study

Background

The significance of studying Kinesiophobia, Limits of Stability (LOS), and functional balance in geriatric patients with CLBP and osteoporosis lies in their profound impact on rehabilitation outcomes and fall risk, ultimately affecting patients' quality of life. This study aimed to examine LOS and functional balance in the geriatric population concurrently experiencing Chronic Low Back Pain (CLBP) and osteoporosis, in comparison to age-matched healthy controls; to assess the correlations between Kinesiophobia, LOS, and functional balance assessments; and to evaluate the mediating influence of Kinesiophobia on the association between LOS and functional balance tests.

Methods

This cross-sectional study included a total of 86 participants in each group. Kinesiophobia was assessed using the Tampa Scale of Kinesiophobia (TSK). LOS variables were evaluated with a computerized Iso-free platform in eight different directions. Functional balance was measured using the Timed Up and Go (TUG) test and the Berg Balance Scale (BBS).

Results

Patients with CLBP and osteoporosis showed significantly lower LOS percentages (45.78 ± 6.92) and impaired Functional Balance, reflected in a TUG Score (10.45 ± 2.23), compared to asymptomatic controls (LOS: 76.95 ± 8.21; TUG: 8.73 ± 1.90). Kinesiophobia showed a significant moderate negative correlation with LOS, indicated by r = -0.362 (p < 0.01). Additionally, Kinesiophobia was found to correlate with functional balance tests. Specifically, there was a moderate positive correlation with the TUG Score (r = 0.322, p < 0.01), indicating that higher Kinesiophobia is associated with slower TUG performance. Conversely, a stronger moderate negative correlation was observed with the Berg Balance Scale (BBS) Score (r = -0.436, p < 0.001), suggesting that increased Kinesiophobia is associated with lower BBS scores, indicating poorer balance performance. Mediation analysis revealed that Kinesiophobia significantly influences LOS and Functional Balance. For LOS and the TUG score, Kinesiophobia showed a direct effect (B = 0.24), an indirect effect (B = 0.09), and a total effect (B = 0.13). Similarly, for LOS and the BBS score, the direct effect of Kinesiophobia was B = 0.38, with an indirect effect of B = 0.10 and a total effect of B = 0.20.

Conclusion

This study underscores the substantial impact of Kinesiophobia on both stability and functional balance in individuals coping with CLBP and osteoporosis. The findings emphasize the clinical relevance of addressing Kinesiophobia as a potential target for interventions aimed at improving LOS and functional balance in this specific patient population.

Is Acute Lower Back Pain Associated with Heart Rate Variability Changes? A Protocol for Systematic Reviews

Acute lower back pain (ALBP) is an extremely common musculoskeletal problem. ALBP consists of a sudden onset of short-duration pain in the lower back. However, repeated attacks can make the pain chronic. It can be measured through a self-report scale as well as through physical and physiological evaluations. Heart Rate Variability (HRV) has been used to evaluate the body's response to pain. However, to the best of our knowledge, no clear consensus has been reached regarding the relationship between both variables and on an optimal protocol for ALBP evaluation based on HRV. The objective of this review is to analyze the relationship and effectiveness of HRV as an instrument for measuring ALBP. Furthermore, we consider the influence of different types of interventions in this relationship. The protocol of this review was previously recorded in the International Prospective Register of Systematic Reviews (number CRD42023437160). The PRISMA guidelines for systematic reviews and PubMed, WOS and Scopus databases are employed. Studies with samples of adults with ALBP are included. This study sets out a systematic review protocol to help identify the relationship between HRV and ALBP. Understanding this relationship could help in designing early detection or action protocols that alleviate ALBP.

Type I collagen concentration affects neurite outgrowth of adult rat DRG explants by altering mechanical properties of hydrogels

Type I collagen is a predominant fibrous protein that makes up the extracellular matrix. Collagen enhances cell attachment and is commonly used in three-dimensional culture systems, to mimic the native extracellular environment, for primary sensory neurons such as dorsal root ganglia (DRG). However, the effects of collagen concentration on adult rat DRG neurite growth have not been assessed in a physiologically relevant, three-dimensional culture. This study focuses on the effects of type I collagen used in a methacrylated hyaluronic acid (MAHA)-laminin-collagen gel (triple gel) on primary adult rat DRG explants in vitro. DRGs were cultured in triple gels, and the neurite lengths and number of support cells were quantified. Increased collagen concentration significantly reduced neurite length but did not affect support cell counts. Mechanical properties, fiber diameter, diffusivity, and mesh size of the triple gels with varying collagen concentration were characterized to further understand the effects of type I collagen on hydrogel property that may affect adult rat DRG explants. Gel stiffness significantly increased as collagen concentration increased and is correlated to DRG neurite length. Collagen concentration also significantly impacted fiber diameter but there was no correlation with DRG neurite length. Increasing collagen concentration had no significant effect on mesh size and diffusivity of the hydrogel. These data suggest that increasing type I collagen minimizes adult rat DRG explant growth in vitro while raising gel stiffness. This knowledge can help develop more robust 3D culture platforms to study sensory neuron growth and design biomaterials for nerve regeneration applications.

Fatty infiltration of the erector spinae at the upper lumbar spine could be a landmark for low back pain

PURPOSE

Intervertebral disc degeneration (IVDD), Modic changes, and fatty infiltration in the paraspinal muscles are possible causes of low back pain (LBP). Multifidus has been the most commonly blamed paraspinal muscle in the etiology of LBP. However, it contributes to 20% of the extensor moment on the lumbar spine. In the present study, we aimed to identify whether patients with LBP and asymptomatic subjects differed in terms of intervertebral discs, end-plates, and fatty infiltration in their paraspinal muscles.

METHODS

Consecutive women and men, who visited the spine outpatient clinics with chronic LBP and had lumbar spine MRI for their LBP without leg pain were included. Asymptomatic subjects without LBP/leg pain for the last year were recruited. Modic changes, IVDD, and fatty infiltration in the paraspinal muscles were evaluated on lumbar spine magnetic resonance imagings of the patients with LBP and age-, gender- and BMI-matched asymptomatic controls.

RESULTS

Low back pain was closely associated with fatty infiltration in the paraspinal muscles at all lumbar levels whereas it had association with severe IVDD and Modic changes at lower lumbar levels. Multifidus at the lower lumbar levels was the fattiest paraspinal muscle in both asymptomatic subjects and patients with LBP. Patients with LBP had severe fatty infiltration in the erector spinae at the upper lumbar levels.

CONCLUSION

Severe IVDD and Modic changes were more common at lower lumbar levels in patients with LBP. Both asymptomatic subjects and those with LBP had fatty multifidus at lower lumbar levels, whereas those with LBP had fatty infiltration in the erector spinae at upper lumbar levels. We suggest that fatty infiltration could have started in the multifidus. The erector spinae had greater contribution to the lumbar extension compared to the multifidus. Thus, LBP could develop when the quality of the erector spinae at the upper lumbar levels impairs due to fatty infiltration.

Conservative Management of Acute Sports-Related Concussions: A Narrative Review

This review explores the application of the conservative management model for pain to sports-related concussions (SRCs), framing concussions as a distinct form of pain syndrome with a pathophysiological foundation in central sensitization. Drawing parallels with proven pain management models, we underscore the significance of a proactive approach to concussion management. Recognizing concussions as a pain syndrome allows for the tailoring of interventions in alignment with conservative principles. This review first covers the epidemiology and controversies surrounding prolonged concussion recovery and persistent post-concussion symptoms (PPCS). Next, the pathophysiology of concussions is presented within the central sensitization framework, emphasizing the need for early intervention to mitigate the neuroplastic changes that lead to heightened pain sensitivity. Five components of the central sensitization process specific to concussion injuries are highlighted as targets for conservative interventions in the acute period: peripheral sensitization, cerebral metabolic dysfunction, neuroinflammation, glymphatic system dysfunction, and pain catastrophizing. These proactive interventions are emphasized as pivotal in accelerating concussion recovery and reducing the risk of prolonged symptoms and PPCS, in line with the philosophy of conservative management.

Differences in musculoskeletal dysfunctions and in postural alterations between chronic migraine and chronic tension type headache: A cross-sectional study

OBJECTIVE

The aim of present study is to assess postural alterations and musculoskeletal dysfunctions over all spine in patients with chronic migraine and chronic tension type headache, moreover to highlight the differences between these two forms of primary headache.

METHODS

A Cross sectional study was adopted to evaluate the musculoskeletal profile in patients with chronic migraine and with chronic tension type headache. The Bio photogrammetric evaluation was performed using the postural assessment software PAS/SAPO, while unilateral passive accessory intervertebral motion (PAIMs) were applied for manual examinations of spine segments from C0 to L5 vertebra. The One-way Analysis of Variance (ANOVA) test was used to compare the three groups with the software GraphPad InStat 3.06.

RESULTS

A total of 60 patients were recruited, 20 for chronic tension type group, 20 for chronic migraine group and 20 healthy controls. The most interesting findings was that patients with chronic primary headaches presented postural alterations in all parameters (cranio-vertebral angle and lumbar-pelvic angle) and musculoskeletal dysfunctions in all spine with respect to healthy controls. Finally, the most clinically relevant finding was that no differences were found between chronic migraine and chronic tension type headache concerning the postural alterations nor the musculoskeletal dysfunctions.

CONCLUSION

The sensitization acts as a substrate or consequence of these musculoskeletal dysfunctions in chronic primary headache. Therefore, non-pharmacological treatments targeted in the musculoskeletal system may be a good option in the management of chronic primary headache, especially when these therapies integrate various techniques that involve all spine.

Sustained acoustic medicine treatment of discogenic chronic low back pain: A randomized, multisite, double-blind, placebo-controlled trial

BACKGROUND

Sustained acoustic medicine (SAM) is a noninvasive long-term treatment that provides essential mechanical and thermal stimulus to accelerate soft tissue healing, alleviate pain, and improve physical activity. SAM increases localized deep tissue temperature, blood flow, cellular proliferation, migration, and nutrition exchange, resulting in reduced inflammation and an increased rate of tissue regeneration.

OBJECTIVE

To assess the efficacy of SAM treatment of discogenic back pain in the lower spinal column to reduce pain, improve quality of life, and lower pharmacotherapy use.

METHODS

Sixty-five subjects with chronic low back pain were randomly assigned to SAM (N= 33) or placebo (N= 32) groups. Subjects self-applied SAM device bilaterality on the lower lumbar region for 4 hours daily for 8 weeks and completed daily pain diaries before, during, and after treatment. Subjects recorded pain reduction using a numeric rating scale (NRS), medication use, and physical activity using the Global Rating of Change (GROC) and Oswestry Disability Index (ODI).

RESULTS

SAM treatment significantly reduced chronic lower back pain from baseline relative to placebo treatment (p< 0.0001). SAM treated subjects reported significantly lower back pain at 4 weeks, with the highest pain reduction (-2.58 points NRS, p< 0.0001) reported at 8 weeks. Similar trends were observed in improved physical activity (3.48 GROC, p< 0.0001, 69-88% ODI, p< 0.0001) and 22.5% (15.2 morphine milligram equivalent) reduction in the use of opioid medication from baseline to 8 weeks.

CONCLUSION

Daily, home-use SAM treatment significantly improves the clinical symptoms of chronic lower back pain, improves physical mobility, and reduces daily medication use. SAM treatment is well-tolerated by patients and may be considered a safe, non-invasive treatment option for chronic discogenic, lower back pain.

Protectin D1 ameliorates non-compressive lumbar disc herniation through SIRT1-mediated CGRP signaling

Background. Neuro-inflammatory response promotes the initiation and sustenance of lumbar disc herniation (LDH). Protectin D1 (PD1), as a new type of specialized pro-resolving mediator (SPM), can improve the prognosis of various inflammatory diseases. Recent studies have shown that over representation of calcitonin gene-related peptides (CGRP) may activate nociceptive signaling following nerve injury. Silent information regulator 1 (SIRT1) is ubiquitously expressed in the dorsal horn of the spinal cord and plays a role in the pathogenesis of LDH. In this study, we investigated the analgesic effects of PD1 and elucidated the impact of neurogenic inflammation in the pathogenesis of neuropathic pain induced by non-compressive lumbar disc herniation (NCLDH) in a rat model. Methods. NCLDH models were established by applying protruding autologous nucleus pulposus to the L5 Dorsal root ganglion (DRG). PD1, SIRT1 antagonist or agonist, CGRP or antagonist were administered as daily intrathecal injections for three consecutive days postoperatively. Behavioral tests were conducted to assess mechanical and thermal hyperalgesia. The ipsilateral lumbar (L4-6) segment of the spinal dorsal horn was isolated for further analysis. Alterations in the release of SIRT1 and CGRP were explored using western blot and immunofluorescence. Results. Application of protruded nucleus (NP) materials to the DRG induced mechanical and thermal allodynia symptoms, and deregulated the expression of pro-inflammatory and anti-inflammatory cytokines in rats. Intrathecal delivery of PD1 significantly reversed the NCLDH-induced imbalance in neuro-inflammatory response and alleviated the symptoms of mechanical and thermal hyperalgesia. In addition, NP application to the DGRs resulted the spinal upregulation of CGRP and SIRT1 expression, which was almost restored by intrathecal injection of PD1 in a dose-dependent manner. SIRT1 antagonist or agonist and CGRP or antagonist treatment further confirmed the result. Conclusion. Our findings indicate PD1 has a potent analgesic effect, and can modulate neuro-inflammation by regulating SIRT1-mediated CGRP signaling in NCLDH.

A model for personalized diagnostics for non-specific low back pain: the role of the myofascial unit

Low back pain (LBP) is the leading cause of disability worldwide. Most LBP is non-specific or idiopathic, which is defined as symptoms of unknown origin without a clear specific cause or pathology. Current guidelines for clinical evaluation are based on ruling out underlying serious medical conditions, but not on addressing underlying potential contributors to pain. Although efforts have been made to identify subgroups within this population based on response to treatment, a comprehensive framework to guide assessment is still lacking. In this paper, we propose a model for a personalized mechanism-based assessment based on the available evidence that seeks to identify the underlying pathologies that may initiate and perpetuate central sensitization associated with chronic non-specific low back pain (nsLBP). We propose that central sensitization can have downstream effects on the "myofascial unit", defined as an integrated anatomical and functional structure that includes muscle fibers, fascia (including endomysium, perimysium and epimysium) and its associated innervations (free nerve endings, muscle spindles), lymphatics, and blood vessels. The tissue-level abnormalities can be perpetuated through a vicious cycle of neurogenic inflammation, impaired fascial gliding, and interstitial inflammatory stasis that manifest as the clinical findings for nsLBP. We postulate that our proposed model offers biological plausibility for the complex spectrum of clinical findings, including tissue-level abnormalities, biomechanical dysfunction and postural asymmetry, ecological and psychosocial factors, associated with nsLBP. The model suggests a multi-domain evaluation that is personalized, feasible and helps rule out specific causes for back pain guiding clinically relevant management. It may also provide a roadmap for future research to elucidate mechanisms underlying this ubiquitous and complex problem.

Objective Measurement of Subjective Pain Perception with Autonomic Body Reactions in Healthy Subjects and Chronic Back Pain Patients: An Experimental Heat Pain Study

Multiple attempts to quantify pain objectively using single measures of physiological body responses have been performed in the past, but the variability across participants reduces the usefulness of such methods. Therefore, this study aims to evaluate whether combining multiple autonomic parameters is more appropriate to quantify the perceived pain intensity of healthy subjects (HSs) and chronic back pain patients (CBPPs) during experimental heat pain stimulation. HS and CBPP received different heat pain stimuli adjusted for individual pain tolerance via a CE-certified thermode. Different sensors measured physiological responses. Machine learning models were trained to evaluate performance in distinguishing pain levels and identify key sensors and features for the classification task. The results show that distinguishing between no and severe pain is significantly easier than discriminating lower pain levels. Electrodermal activity is the best marker for distinguishing between low and high pain levels. However, recursive feature elimination showed that an optimal subset of features for all modalities includes characteristics retrieved from several modalities. Moreover, the study's findings indicate that differences in physiological responses to pain in HS and CBPP remain small.

Composite Biomarkers, Behavioral Symptoms, and Comorbidities in Axial Low Back Pain: A Systematic Review

PURPOSE

Proinflammatory cytokines play a critical role in chronic inflammation and pain and contribute to behavioral symptoms (depressive symptoms, anxiety, fatigue, sleep disturbance) and comorbidities (diabetes, cardiac diseases, cancer). Evidence is lacking on the specific proinflammatory cytokines associated with these behavioral symptoms/comorbidities co-occurring with axial low back pain (aLBP). This review aimed to systematically analyze the following: (1) specific proinflammatory cytokines associated with aLBP in adults, (2) associations among proinflammatory cytokines and behavioral symptoms in aLBP, and (3) relationships among proinflammatory cytokines and comorbidities in aLBP, to develop a new clinical framework for future diagnostic and intervention targets for patients with aLBP.

METHODS

Electronic databases, including PubMed/MEDLINE, ProQuest Nursing & Allied Health Source, and CINAHL Complete (EBSCO) were searched for the period January 2012 to February 2023. Eligible studies included cross-sectional, case-control, longitudinal, and cohort studies in which proinflammatory cytokines were reported in adults above 18 years with aLBP. Intervention studies and randomized controlled trails were excluded. The Joanna Briggs Institute (JBI) criteria were used for quality evaluation.

RESULTS

Findings from 11 studies showed 3 proinflammatory cytokines associated with pain intensity in adult patients with aLBP: C-Reactive Protein (CRP), Tumor Necrosis Factor (TNF-α), and Interleukin (IL-6). Some studies assessed associations between proinflammatory cytokines and depressive symptoms; none explored the association of proinflammatory cytokines with fatigue, anxiety, sleep disturbance, or comorbidities (diabetes, cardiac diseases, and cancer) in aLBP.

CONCLUSIONS

Proinflammatory cytokines in aLBP can serve as composite biomarkers for pain, associated symptoms, and comorbidities and may serve as a target for future interventions. There is need for well-designed studies assessing associations among chronic inflammation, behavioral symptoms, and comorbidities.

Mechanism, application and effect evaluation of nerve mobilization in the treatment of low back pain: A narrative review

Lower back pain is a prevalent condition affecting people across all age groups and causing significant personal and societal burdens. While numerous treatments exist, nerve mobilization has emerged as a promising approach for managing lower back pain. Nerve mobilization involves applying gentle and rhythmic movements to the affected nerves, promoting normal nerve function and releasing tension. It has been well documented that nerve mobilization can be effective in reducing pain and improving function in patients with lower back pain, but the underlying mechanisms have not been clarified. This study aims to review the mechanisms of nerve mobilization in the management of lower back pain, its application, and effectiveness evaluation, and provide a potential solution for managing lower back pain.

Theoretical Schemas to Guide Back Pain Consortium (BACPAC) Chronic Low Back Pain Clinical Research

BACKGROUND

Chronic low back pain (cLBP) is a complex with a heterogenous clinical presentation. A better understanding of the factors that contribute to cLBP is needed for accurate diagnosis, optimal treatment, and identification of mechanistic targets for new therapies. The Back Pain Consortium (BACPAC) Research Program provides a unique opportunity in this regard, as it will generate large clinical datasets, including a diverse set of harmonized measurements. The Theoretical Model Working Group was established to guide BACPAC research and to organize new knowledge within a mechanistic framework. This article summarizes the initial work of the Theoretical Model Working Group. It includes a three-stage integration of expert opinion and an umbrella literature review of factors that affect cLBP severity and chronicity.

METHODS

During Stage 1, experts from across BACPAC established a taxonomy for risk and prognostic factors (RPFs) and preliminary graphical depictions. During Stage 2, a separate team conducted a literature review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to establish working definitions, associated data elements, and overall strength of evidence for identified RPFs. These were subsequently integrated with expert opinion during Stage 3.

RESULTS

The majority (∼80%) of RPFs had little strength-of-evidence confidence, whereas seven factors had substantial confidence for either a positive association with cLBP (pain-related anxiety, serum C-reactive protein, diabetes, and anticipatory/compensatory postural adjustments) or no association with cLBP (serum interleukin 1-beta / interleukin 6, transversus muscle morphology/activity, and quantitative sensory testing).

CONCLUSION

This theoretical perspective will evolve over time as BACPAC investigators link empirical results to theory, challenge current ideas of the biopsychosocial model, and use a systems approach to develop tools and algorithms that disentangle the dynamic interactions among cLBP factors.

Influence of weight-bearing on the 3D movement of lumbar facet joints in the sitting position

OBJECTIVE

To analyze the motion characteristics of lumbar facet joints and to observe the effect of weight-bearing on lumbar facet joints in the sitting position.

METHODS

Ten normal subjects (5 males and 5 females) were recruited and scanned by CT, and their lumbar 3D models were reconstructed by software. The images of flexion and extension of lumbar facet joints in the sitting position were collected without weight-bearing and weight-bearing 10 kg, and the 2D model was constructed by software. The 2D-3D model was matched to restore the flexion and extension motion changes of the subjects' lumbar spine in the sitting position. Coordinates were established in the middle of the vertebral body and copied to the facet joints. Measure and record the lumbar facet joint movement distance through coordinate system. The relevant data of facet joints were collected.

RESULTS

In the L3/4 segment, after weight loading, the displacement of the left facet joint in the X axis became larger, while that in the Y axis and Z axis decreased. The displacement of the right facet joint in the X axis and Y axis increased, and the Z axis displacement decreased. The rotation angle of the bilateral facet joints also decreased. In the L4/5 segment, after loading, the displacements of the X, Y, and Z axis displacements of both sides increase, while the rotation angles of α and β increase, while the rotation angle of γ decreases. In the L5/S1 segment, the displacements of the X, Y, and Z axes on the left side decrease. The displacement of the X and Y axes on the right side decreases, while the displacement on the Z axis increases. The rotation angles of α and γ increase, and the rotation angle of the β axis decreases.

CONCLUSION

When sitting, the flexion and extension distance and rotational displacement of lumbar facet joints are not affected by weight-bearing. In addition, there is asymmetry in the movement of the left and right facet joints, and weight bearing has no effect on the asymmetry of the motion.

Relationship between Time Elapsed Since Pain Onset and Efficacy of Pain Relief in Patients Undergoing Lumbar Percutaneous Epidural Adhesiolysis

PURPOSE

The aim of this study was to investigate the relationship between pain duration and pain relief after epidural adhesiolysis.

MATERIALS AND METHODS

Patients with low back pain who underwent lumbar epidural adhesiolysis were enrolled. A clinically significant reduction in pain score was defined as a ≥30% reduction at 6-month follow-up evaluation. Variables were compared based on pain duration categories. Changes in pain scores and pain outcome were also compared. Logistic regression analysis was conducted to identify factors associated with pain relief after adhesiolysis.

RESULTS

A total of 169 patients, including 77 (45.6%) patients with a favorable pain outcome, were included for analysis. Patients with a pain duration ≥3 years reported lower baseline pain scores and showed more frequent severe central stenosis. Pain scores significantly decreased over time after the procedure except in patients with a pain duration ≥3 years. Most patients who experienced pain for ≥3 years showed poor pain relief (80.8%), unlike other pain duration categories (pain duration <3 months=48.1%, 3 months-1 year=51.8%, 1-3 years=48.6%). A pain duration ≥3 years and lower baseline pain score were independent factors associated with an unfavorable pain outcome.

CONCLUSION

Pain lasting ≥3 years prior to lumbar epidural adhesiolysis was associated with worse outcomes in terms of pain relief. Therefore, this intervention should be considered early before pain chronification in patients with low back pain.

One immune system plays many parts: The dynamic role of the immune system in chronic pain and opioid pharmacology

The transition from acute to chronic pain is an ongoing major problem for individuals, society and healthcare systems around the world. It is clear chronic pain is a complex multidimensional biological challenge plagued with difficulties in pain management, specifically opioid use. In recent years the role of the immune system in chronic pain and opioid pharmacology has come to the forefront. As a highly dynamic and versatile network of cells, tissues and organs, the immune system is perfectly positioned at the microscale level to alter nociception and drive structural adaptations that underpin chronic pain and opioid use. In this review, we highlight the need to understand the dynamic and adaptable characteristics of the immune system and their role in the transition, maintenance and resolution of chronic pain. The complex multidimensional interplay of the immune system with multiple physiological systems may provide new transformative insight for novel targets for clinical management and treatment of chronic pain. This article is part of the Special Issue on "Opioid-induced changes in addiction and pain circuits".

Low Back Pain and Radiofrequency Denervation of Facet Joint: Beyond Pain Control-A Video Recording

Chronic low back pain is often due to L5S1 instability resulting in facet joint syndrome. Patients suffering from low back pain may also have a gait pattern characterized by a reduced speed and a shorter, asymmetrical step in order to reduce pain. This case is of a patient with L5S1 instability that occurred after L1 to L5 lumbar stabilization who was treated with radiofrequency (RF) denervation of the medial branch of L5S1 bilaterally. RF ablation outcome was tested by comparing its impact on pain, function, quality of life, and on gait pattern, before and 1 month after the procedure. To objectify the impact of a good pain control on gait, a video recording was performed (see Video 1).

Intervertebral disc degeneration and how it leads to low back pain

The purpose of this review was to evaluate data generated by animal models of intervertebral disc (IVD) degeneration published in the last decade and show how this has made invaluable contributions to the identification of molecular events occurring in and contributing to pain generation. IVD degeneration and associated spinal pain is a complex multifactorial process, its complexity poses difficulties in the selection of the most appropriate therapeutic target to focus on of many potential candidates in the formulation of strategies to alleviate pain perception and to effect disc repair and regeneration and the prevention of associated neuropathic and nociceptive pain. Nerve ingrowth and increased numbers of nociceptors and mechanoreceptors in the degenerate IVD are mechanically stimulated in the biomechanically incompetent abnormally loaded degenerate IVD leading to increased generation of low back pain. Maintenance of a healthy IVD is, thus, an important preventative measure that warrants further investigation to preclude the generation of low back pain. Recent studies with growth and differentiation factor 6 in IVD puncture and multi-level IVD degeneration models and a rat xenograft radiculopathy pain model have shown it has considerable potential in the prevention of further deterioration in degenerate IVDs, has regenerative properties that promote recovery of normal IVD architectural functional organization and inhibits the generation of inflammatory mediators that lead to disc degeneration and the generation of low back pain. Human clinical trials are warranted and eagerly anticipated with this compound to assess its efficacy in the treatment of IVD degeneration and the prevention of the generation of low back pain.

Inflammatory Blood Signature Related to Common Psychological Comorbidity in Chronic Pain

Chronic pain is characterized by high psychological comorbidity, and diagnoses are symptom-based due to a lack of clear pathophysiological factors and valid biomarkers. We investigate if inflammatory blood biomarker signatures are associated with pain intensity and psychological comorbidity in a mixed chronic pain population. Eighty-one patients (72% women) with chronic pain (>6 months) were included. Patient reported outcomes were collected, and blood was analyzed with the Proseek Multiplex Olink Inflammation Panel (Bioscience Uppsala, Uppsala, Sweden), resulting in 77 inflammatory markers included for multivariate data analysis. Three subgroups of chronic pain patients were identified using an unsupervised principal component analysis. No difference between the subgroups was seen in pain intensity, but differences were seen in mental health and inflammatory profiles. Ten inflammatory proteins were significantly associated with anxiety and depression (using the Generalized Anxiety Disorder 7-item scale (GAD-7) and the Patient Health Questionnaire (PHQ-9): STAMBP, SIRT2, AXIN1, CASP-8, ADA, IL-7, CD40, CXCL1, CXCL5, and CD244. No markers were related to pain intensity. Fifteen proteins could differentiate between patients with moderate/high (GAD-7/PHQ-9 > 10) or mild/no (GAD-7/PHQ-9 < 10) psychological comorbidity. This study further contributes to the increasing knowledge of the importance of inflammation in chronic pain conditions and indicates that specific inflammatory proteins may be related to psychological comorbidity.

Mechanisms of Transmission and Processing of Pain: A Narrative Review

Knowledge about the mechanisms of transmission and the processing of nociceptive information, both in healthy and pathological states, has greatly expanded in recent years. This rapid progress is due to a multidisciplinary approach involving the simultaneous use of different branches of study, such as systems neurobiology, behavioral analysis, genetics, and cell and molecular techniques. This narrative review aims to clarify the mechanisms of transmission and the processing of pain while also taking into account the characteristics and properties of nociceptors and how the immune system influences pain perception. Moreover, several important aspects of this crucial theme of human life will be discussed. Nociceptor neurons and the immune system play a key role in pain and inflammation. The interactions between the immune system and nociceptors occur within peripheral sites of injury and the central nervous system. The modulation of nociceptor activity or chemical mediators may provide promising novel approaches to the treatment of pain and chronic inflammatory disease. The sensory nervous system is fundamental in the modulation of the host's protective response, and understanding its interactions is pivotal in the process of revealing new strategies for the treatment of pain.